66 Dr. A. Voeltzkow on the Oviposition and 



Criuoicl morphology to regard their resemblances as due to 

 liomogeny rather than to homoplasy. 



Imperforate Articulation. 



Eeference to " British Fossil Crinoids," II. p. 314, will 

 show that there is some diflSculty in distinguishing between 

 those forms of joint that are there called " Loose suture " 

 and " ]\luscular articulation." There are among Inadunate 

 Crinoids many instances of arm-joints in which there is a 

 well-defined fulcral ridge, combined with muscular and liga- 

 mental depressions, but in which the axial canal does not 

 happen to be separated from the ventral groove by stereom 

 and so does not perforate the fulcral ridge. It might be 

 advisable to distinguish these joints as " Imperforate articu- 

 lation," and to call the muscular articulation in which ^' the 

 articular ridge, whether vertical or transverse, is always 

 perforate," " Perforate articulation." 



It is unfortunately necessary to explain that the word 

 "joint " is used here and throughout my papers in its ordinary 

 English and anatomical sense, and not in that restricted and 

 different sense which is usually ascribed to it by crinoidolo- 

 gists and cooks. 



VIII. — On the Oviposition and Embryonic Development of 

 the Crocodile. By Dr. A. Voeltzkow, of Majunga, 

 Madagascar *. 



The Madagascar Crocodile, Crocodilus niloticus,IjauY. [mada- 

 gascariensisj Grandid.), is not only one of the commonest 

 reptiles, but perhaps the commonest Vertebrate of the ishind. 

 It i» found in large numbers wherever there is water, in every 

 ])ool and stream. The natives distinguish two species, one 

 {Cr. niloticiis) with a longer, and another with a shorter head 

 and greater length of body ; the latter is said to occur only 

 in the large rivers in the primeval forest, and the natives are 

 extraordinarily afraid of it, as it is stated to be very savage ; 

 it is probably identical with Cr. rohustus, VailL, Grandid. I 



* Translated from the * Mathematische und Naturvrisseuscbaftliche 

 Mittlieiliuigeu aus den Sitzungsbericliten der Koniglich Preussischen 

 Akademie der Wissenschaften zu Berlin,' Heft ii., ISUl, pp. fllol 51-50 



[120]. 



